This invention relates generally to food or feed products and processes. More particularly, this invention relates to a process for enhancing the protein content of food or feed products. Additionally the invention relates to food and feed products having an increased protein content as produced by the subject process.
One of the most serious problems which the world faces is supplying nutritionally adequate protein to meet the demands of a population which is expanding by approximately 55 million people annually. If the average protein requirement for an individual is about 52 pounds per year, this means that there must be produced an additional 2.8 billion pounds of protein each year just to keep pace with the population increase. This does not take into account the fact that much of the present world population does not have sufficient protein in their diet to be healthy enough to lead meaningful lives. Thus, there is a very pressing need for ways of increasing the total protein production of the world.
A problem associated with the need to supply adequate protein for the world population is the fact that cereal grains and cereal grain products make up a high percentage of the diet of most of the developing nations. Unfortunately, these grains and grain products usually contain 10% or less protein which is very often deficient in some of the essential amino acids. Since the average person requires at least 65 grams of high quality protein per day for good health, this means that an intake of 650 grams of cereal grains would be required to supply this quantity of protein. Ingesting this much cereal grain would supply too much carbohydrate relative to the amount of protein. Furthermore, the protein contained within these cereal grains is generally of relatively poor quality.
The present invention is directed to a solution to the above-described problems by increasing the ratio of protein to carbohydrate in cereal grains and products thereof while concominantly improving the overall amino acid balance for the treated grain.
Much of the grain grown in the world is fed to monogastric animals (swine, chickens, etc.) who have roughly the same nutritional requirements as man. Accordingly, the present invention would lead to economy in feeding these animals since it would not be necessary to add protein supplements to these grains (soy bean meal, cotton seed meal, fish meal, etc.) if the animals were fed grains treated by the process of the present invention.
Studies have been made in the past to develope processes for treating various foods containing carbohydrates with lower fungi so as to increase their protein content. The process suggested in such studies, however, are less desirable than the process of the present invention because these other processes either require "fixed" inorganic nitrogen, or produce nutritionally deficient protein, or require separation of the protein to produce an acceptable food or feedstuff.
On the other hand, the present process suffers from none of these drawbacks. A food or foodstuff such as a cereal grain (wheat, corn, and the like) treated by the instant process may be dried to the customary moisture levels and processed by conventional methods to provide food and feed products such as bread, dry cereal products, dog and cat foods and the like which contain enough high quality protein to be nutritionally well balanced and have a flavor which is highly acceptable.
Additionally concepts have previously been disclosed relating to the art of cultivating mushrooms from a mycelium of the genus Pleurotus including Pleurotus ostreatus, Pleurotus ulmariums, Pleurotus sapidus, Pleurotus cornucopiae, and Pleurotus florida.
At least one publication suggests that mushrooms may be cultivated in a culture medium comprising, for example, corn fibers and rice bran (or corn bran) and subsequently the cultivation medium may be used as feedstuff.
At least one other previously known publication discloses that a nutrient substance which comprises one or more cellulose-containing agricultural waste products may be crushed, mixed with water and placed into a ventilated container which is sterilized. The sterilization is carried out either by heating to 70.degree. to 80.degree. C. for 5 hours or by introducing propylene oxide. After the mixture is placed inside the sterilized container, it is injected with a mycelium of the fungus Pleurotus ostreatus. The nutrient substance is preferably wheat, barley, rye, peas, rice shells, sun flower stalks and seeds.
The container is kept at a constant temperature between 16.degree. and 20.degree. C. after seeding. When the nutrient is permeated with the mycelium, the temperature is lowered to between 5.degree. and 16.degree. C. After the onset of the crop of mushrooms, the container is opened and illuminated with light.
Still another theorist suggests that a substrate such as seed oil residues (e.g., cottonseed meal, coconut meal, peanut meal, etc.) which are advantageously mixed with a cereal material such as wheat or the like may be innoculated with a mycelium of mushrooms including, among others, Pleurotus ostreatus. The substrate (e.g., peanut meal) is first acid hydrolyzed by treating it with mineral acid. The calcium carbonate is added and the pH is adjusted to between 6 and 8. This mixture is then innoculated with the mycelium of mushrooms (e.g., Pleurotus ostreatus) which has been grown on a medium of the same composition.
Although the above noted disclosures have at least a degree of conceptual appeal in the art of growing mushrooms, little if any attention has been directed to developing a protein enriched food or food stuff using a spawn culture of the genus Pleurotus. In none of these publications has any mention been made of the fact that Pleurotus will grow in the presence of materials already containing protein (cereal grain and the like) without substantially altering the protein already present, and at the same time produce additional protein by fixing nitrogen which is in the air and using the grain as a source of carbon.